1. Technical Field
The present invention relates to a developing device and an image forming apparatus using the same.
2. Related Art
Electrophotographic image forming apparatuses often use a dual-component developing agent in which toner and magnetic carrier are mixed, or a magnetic monocomponent developing agent having magnetic toner as its primary component. The developing agent is conveyed from a developing agent reservoir portion of a developing device to a developing roll by a conveyance member. The developing agent magnetically adsorbed on the circumferential surface of the developing roll is conveyed to a position (a developing nip portion where a developing pole of the developing roll is located) opposed to a photoconductor drum, and transferred to the photoconductor drum. Thus, an electrostatic latent image formed on the photoconductor drum is developed.
Here, of developing devices, there is a two-stage type developing device in which developing rolls are provided above and below in two stages so as to ensure development in order to cope with the increasing speed of an image forming apparatus.